Formulation of Hydrogel from Synthesized Silica-Reinforced Poly(Acrylamide/PVP) Polymer for Water Shut-Off in...

The present study investigates the synthesis of silica-enforced poly-(acrylamide/polyvinylpyrrolidone) (AM/PVP) polymer and its properties in formulating a hydrogel for conformance control in high-salinity reservoirs. The synthesis of polyvinylpyrrolidone (PVP)-acrylamide (AM) copolymer and the presence of silica in its structure were confirmed through FTIR spectroscopy, in addition to the evaluation of characteristics including rheology, thermal stability, swelling characteristic, and pore-plugging capability through various analytical studies. The nanohydrogel of the synthesized silica-PVP-AM copolymer displays prominent shear-thinning, viscoelastic behavior, with the elastic modulus (G') higher than the viscous modulus (G″). The DSC results indicate an increase of approximately 22 °C (from ∼131 °C to ∼152 °C) in the glass transition temperature (T _g) of the silica-impregnated copolymer hydrogel compared to the gel in the absence of silica nanoparticles, suggesting a notable improvement in its thermal stability compared to its counterpart. An increased bound water-holding capacity from 25.26% to 33.39% was observed in the nanohydrogel compared to its counterpart, which was further confirmed by the microstructure of the hydrogels observed in FESEM images. The efficacy of the hydrogel was further evaluated through sandpack experiments, with 95.7% permeability reduction of the sandpack after placement of the nanohydrogel, proving its capability in controlling water channeling.